Explosion resistance performance of reinforced concrete box girder coated with polyurea: Model test and numerical simulation

Abstract

To study the anti-explosion protection effect of polyurea coating on reinforced concrete box girder, two segmental girder specimens were made at a scale of 1:3, numbered as G (without polyurea coating) and PCG (with polyurea coating). The failure characteristics and dynamic responses of the specimens were compared through conducting explosion tests. The reliability of the numerical simulation using LS-DYNA software was verified by the test results. The effects of different scaled distances, reinforcement ratios, concrete strengths, coating thicknesses and ranges of polyurea were studied. The results show that the polyurea coating can effectively enhance the anti-explosion performance of the girder. The top plate of middle chamber in specimen G forms an elliptical penetrating hole, while that in specimen PCG only shows a very slight local dent. The peak vertical displacement and residual displacement of PCG decrease by 74.8% and 73.7%, respectively, compared with those of specimen G. For the TNT explosion with small equivalent, the polyurea coating has a more significant protective effect on reducing the size of fracture. With the increase of TNT equivalent, the protective effect of polyurea on reducing girder displacement becomes more significant. The optimal reinforcement ratio, concrete strength, thickness and range of polyurea coating were also drawn.